Diagnostic accuracy of semirigid thoracoscopy in exudative pleural effusions and relationship of thoracoscopic findings with probability of malignant diagnosis

Prospective Evaluation of Safety and Diagnostic Efficacy of Medical Thoracoscopy in Undiagnosed Exudative Pleural Effusion: Experience From a Tuberculosis High-Burden Country

INTRODUCTION

Pleural effusion is due to the pathological accumulation of pleural fluid in the pleural space, 25%-30% of which may remain undiagnosed despite the combination of biochemical, microbiological, and pathological tests and closed pleural biopsy. Medical thoracoscopy may help physicians diagnose such cases. We aimed to study the diagnostic yield of medical thoracoscopy in patients with undiagnosed exudative pleural effusion and assess the safety profile of the medical thoracoscopy.

METHODOLOGY

A cross-sectional descriptive study was conducted on 105 patients with undiagnosed pleural effusion. Medical thoracoscopy was performed using an Olympus semi-rigid thoracoscope (LTF 160 Evis Pleurovideoscope, Japan) as per standard protocol. Multiple pleural biopsies were taken and sent for histopathology examination, NAAT (nucleic acid amplification test), and MGIT (mycobacteria growth indicator tube). Post-procedure, the patients were evaluated for any complications.

RESULTS

A total of 105 patients were enrolled in the study. The mean ± SD age was 55.1 ± 13.6 years. Sixty-three (60%) patients were males. The diagnostic utility of medical thoracoscopy was found in 94 (89.5%) patients. The diagnosis of tuberculosis (TB) was made in 34 (32.3%) patients, and 48 (45.7%) patients were diagnosed with malignant pleural effusion. Adenocarcinoma of the lung was the most common malignancy diagnosed (32 patients, 66.6%). Five (5.31%) patients had dual etiology of pleural effusion: tubercular and malignancy. The most common complication was chest pain following the procedure (99.4%). One patient developed pneumomediastinum and was managed conservatively. There were no major adverse events after the procedure.

CONCLUSIONS

Medical thoracoscopy has a high diagnostic yield and favorable safety profile with minimal complications. Excessive reliance on the level of ADA (adenosine deaminase) may further delay the diagnosis. Dual etiologies like TB coexisting with malignancy should be considered in TB high-burden countries.

Comparison of Diagnostic Yield and Complications in Ultrasound-Guided Closed Pleural Biopsy Versus Thoracoscopic Pleural Biopsy in Undiagnosed Exudative Pleural Effusion

Introduction

Malignancy, tuberculosis, and non-tubercular pleural infections account for most exudative pleural effusion. Pleural fluid cytology, biochemical tests and even pleural fluid cell block studies may fail to yield a diagnosis in certain cases. Medical thoracoscopy is the gold standard for the diagnosis of unexplained pleural effusions. However, access to medical thoracoscopy may be limited, particularly in developing countries. Also, certain patients may not be fit to undergo the procedure because of medical conditions. An ultrasound-guided pleural biopsy is an option in such conditions. The present study is intended to compare the diagnostic yield and complications of both methods of pleural biopsy in undiagnosed exudative pleural effusion under a randomized controlled trial.

Method

After fulfilling all the inclusion criteria, participants were randomized to either ultrasound-guided closed pleural biopsy or thoracoscopic-guided pleural biopsy groups. The primary outcome was to compare the diagnostic yield of ultrasound-guided Tru-Cut® (Newtech Medical Devices, Faridabad, India) closed pleural biopsy versus thoracoscopic pleural biopsy, and the secondary outcomes were to compare the complications rate, duration of the procedure, and hospital stay in the patients undergoing ultrasound-guided pleural biopsy versus thoracoscopic pleural biopsy, and predictors of a positive biopsy result in both groups.

Result

A total of 118 patients with pleural effusion were screened; 39 of them who were eligible, randomized into the ultrasound group (20 patients) and the thoracoscopic group (19 patients). The median age of participants was 53.5 (50-58) years and 55 (45-64) years in the ultrasound and thoracoscopic groups, respectively. Pleural fluid cell count, protein, adenosine deaminase (ADA), and lactate dehydrogenase (LDH) were similar in both groups, although pleural fluid glucose was low in the ultrasound group. Diagnostic yield was 90% (18/20) and 94.7% (18/19) in the ultrasound and thoracoscopic groups, respectively, which was statistically non-significant (p=0.963). The median duration of hospital stay was 9.5 (5.3-27) days and 15 (12-22) days in ultrasound and thoracoscopic groups respectively. The thoracoscopic group had a more prolonged stay compared to the ultrasound group, but it was statistically non-significant (p=0.09). The duration of the procedure was significantly longer in the thoracoscopic group 90 (85-105) minutes, in comparison to ultrasound 47.5 (41.3-55) minutes (p=0.001). No major complications were seen in both groups. Subcutaneous emphysema was the most common complication in the thoracoscopic group (10%), followed by hemorrhage (5.3%), and respiratory failure (5.3%). Hypotension was the only complication in the ultrasound group (5%). The rate of complications was significantly higher in the thoracoscopic group (p<0.01).

Conclusion

Ultrasound-guided closed pleural biopsy is as good as thoracoscopic pleural biopsy in undiagnosed exudative pleural effusion. It was associated with a shorter procedure duration, a shorter hospital stay, and fewer complications as compared to thoracoscopic biopsy. Both the procedures were safe in experienced hands and a hospital setup, but the thoracoscopic pleural biopsy was associated with complications.